The present invention relates to devices for punching holes in materials such as paper cards, rubber or leather products. More particularly, the invention relates to a seamless hole puncher and a method for making the same.
Various types of hole punchers have been used in order to punch holes in products. Hole punchers may be used to cut regular shaped holes, e.g. round holes or to cut irregular shaped holes that will allow the product to engage various types of extensions, e.g. round pegs or flat extensions, from which the products are hung. Typical of those products are blister packs, formed by mounting a product to be sold on a paper card and covering the product with a clear plastic coating which secures the product to the card.
Contemporary hole punchers are typically seamless, formed by machining a cutting lip onto a solid mass of metal or formed by bending and welding a length of flat metal to form a seam along the length of the hole puncher. Previous seamless hole punches have been limited to round or oblong punches formed of relatively thick tubing, e.g. approximately 0.062 and 0.049 inches wall thickness. Though such punchers are satisfactory for forming round or oblong shaped holes, the thickness of such punchers and the technique by which they are formed do not lend themselves to the formation of more irregularly shaped hole punchers which can produce holes having greater practical or aesthetic appeal.
Machined hole punches are also typically confined to use in the formation of regular shaped holes. The machinery, skilled labor and attendant expense associated with this method of fabricating hole punches are the principal limiting factors in restricting its commercial application.
Punches that cut holes having irregular shapes, such as holes that will accommodate round and flat extensions, have previously been made by bending ruled steel strips and welding the ends together. That process is complicated and produces a product inferior to the seamless hole punch. There are also a number of other economic aspects of the contemporary bending process which limit the commercial usefulness of that process. For example, the bending process requires expensive bending machinery, which must be carefully set up by skilled labor. Furthermore, the difficulties associated with the production of taller punches, under the conventional bending process, increase with the height of the punch. That increase is due to the difficulty in closely aligning edges of the punch produced by the bending process. That difficulty effectively limits the height of a punch that can be economically produced by the conventional bending process. Such tall punches are useful, for example, in punching holes in paper cards having a raised packaging portion attached to the card, e.g. blister packs.
Accordingly, there is a need to provide a hole puncher and an process for forming a hole punch an apparatus for punching holes which more readily lends itself to mass production techniques to produce hole punchers of various sizes. Furthermore, there is a need for high quality hole punchers which can be produced without the need for highly skilled labor or expensive bending machinery.